HRB400E钢筋混凝土梁柱边节点的抗剪性能

为研究配置HRB400E钢筋混凝土梁柱边节点的抗剪性能,以混凝土强度、水平纵筋锚固方式、梁纵筋配筋率为主要研究参数,采用正交试验法设计了9个试件并完成了梁柱边节点的抗剪试验。试验结果表明:试件多发生梁端弯曲和核心区剪切破坏,但采用弯折锚固方式可有效减少节点核心区裂缝数量；在本文3个研究参数中,混凝土强度对初裂时节点核心区剪切变形影响最大,混凝土强度等级越高初裂阶段的节点剪切变形角越小；水平纵筋锚固方式对极限状态时节点核心区剪切变形影响最大,当采用90°弯折锚固方式时节点的剪切变形角最小；梁纵筋配筋率对节点水平剪力影响最大,配筋率越大节点水平剪力越大。采用正交试验原理结合极差、方差数理统计理论对梁柱边节点抗剪性能影响参数进行分析可梳理出各因素的主次关系和变化趋势。

Shearing performance of concrete exterior beam-column joints with HRB400E reinforcement

To study the shearing performance of concrete exterior beam-column joint with HRB400E reinforcement, we designed nine specimens based on orthogonal test method and conducted shearing test, which takes concrete strength, horizontal reinforcement anchorage arrangement, and reinforcement ratio as the main research parameters. Test results show that beam end bending failure and joint core shear failure were common failure modes of specimens, but bending anchorage arrangement could effectively reduce the number of cracks in the joint core. Among the three parameters, concrete strength had the most influence on the shearing deformation of the joint core, and as the concrete strength grade increased, the shearing deformation angle at the initial crack decreased. The anchorage arrangement of the horizontal bars had the most influence on the shearing deformation of joint core at the ultimate state, and shearing deformation angle reached the minimum value when 90° bending anchorage arrangement was adopted. The ratio of longitudinal reinforcement to beam had the greatest influence on the horizontal shearing force of the joint, and the horizontal shearing force increased with the increase in the reinforcement ratio. The primary and secondary relations of the parameters and corresponding changing trends were analyzed by using the orthogonal test principle combined with the mathematical statistics theory of range and variance.